RSSs are most often used by hospitals and health systems for repeated, ongoing educational sessions that are conducted by and for the organization’s staff. In general, if you are changing a single live, in-person CME course to a live, virtual format, that activity should be categorized instead as an Internet live course, rather than an RSS.
Yes. You can make enduring materials available for as short or as long a period as you choose, as long as the enduring materials continue to meet applicable ACCME requirements. The ACCME requires enduring CME materials to be reviewed (and updated, if necessary) at least once every three years.
For COVID-19-related CME only, you may report the webinar using the "Other" activity format in PARS, and indicate that it was a blended activity. For all other activities, if you are creating both live and enduring materials, then you would need to report those as two separate activities in PARS.